Some days, art is hard. You get up, you stare at the canvas (or watercolor block, or New Painter File,) and there is nothin'. You walk into your studio, and wince away from the accusing white glares of the half-finished paintings that have been half finished for weeks, going on months, and the ones in the back, years. You labor over the smallest stroke. You try to drink from the well of inspiration, and not only is it mostly dry, there's a soggy dead rat at the bottom.
And then again, some days you spend the morning painting vampire cleavage, and you think "Man, I have the best job in the world."